ADU Construction in Altadena
Altadena ADUs with a traced load path from roof to footing, ember-resistant skin for mapped fire hazard lots and county plan review handled for you.
"What keeps the cottage on its foundation when the ground starts rolling?" An Altadena owner deserves a straight answer to that on the first site visit, so we trace it out loud. Roof sheathing hands the shaking to the walls, plywood panels pass it down, and hold-downs at the panel ends pull against bolts cast into the footing. The footing then spreads that force into soil the engineer has measured.
The parts you will never see
Most of what holds an Altadena ADU together is hidden once the drywall goes up. Metal clips join each rafter to the top plate. Nailing at the edges of every shear panel is tighter than in the field of the sheet, and the inspector counts it before the walls are closed. Anchor bolts with square plate washers hold the sill to the concrete. Each piece is called out on the structural sheet, and we photograph the framing before cover so the record survives inside the finished walls.
Siding, vents and the county review
Altadena is an unincorporated community, and Los Angeles County reviews and inspects the ADU. Areas of Altadena are mapped for fire hazard severity, and a lot in one may face ember-resistance rules: a Class A roof, vents with fine metal mesh or listed baffles, tempered glazing and an exterior wall finish that will not ignite. Cement plaster or fiber cement over the sheathing meets those rules and adds stiffness to the wall. A noncombustible strip of gravel or pavers along the base keeps plants off the siding.
About our adu construction serviceEverything we do in Altadena
ADU Construction in Altadena: questions
Reinforced concrete that the engineer sizes from a soils report. An Altadena unit may stand on a slab with deepened perimeter edges, or on a continuous footing carrying a raised wood floor. If the lot slopes, the footing can step or the design can shift to piers. Anchor hardware is fixed in the forms before concrete arrives.
A converted garage keeps its old footing only if digging proves it is deep and wide enough for a home. Garages vary, so at an Altadena property we expose the edge in a few places and measure. If the concrete falls short under a wall that will be braced, a new footing section goes in beside it, bolted and inspected.
Single-story Altadena designs that stay at 500 square feet or smaller fit it. On a lot the fire hazard map covers, the county reviewer reads the wall drawings for vents, siding and glazing, so the package gives that sheet real effort. Bigger units and two-story plans are priced after a look at the lot.
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Describe the house and what it needs. We look at the structure first and send the quote in writing.